This application claims the priority of German application 197 21 752.4-21, filed in Germany on May 24, 1997, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a device for adjusting the toe-in of wheels of motor vehicles, and more particularly to a device for setting the toe-in of wheels of motor vehicles with a bearing eye of a wheel suspension link lying between support arms on the body side, and guiding the bearing eye with respect to the supporting arm, which is adjustable vertically and horizontally for setting the toe-in established for a spring position of the vehicle corresponding to a design position by adjusting disks which in turn are guided on supporting surfaces of the support arm.
The toe-in of an axle is characterized by the so-called "basic toe-in," the toe-in set at an established deflection of the vehicle springs and the tilt or the tilt of the toe-in curve in space over the spring travel. During manufacture, the toe-in is adjusted, and during the life of the vehicle it is routinely checked in service inspections, because even slight deviations have a profound effect on performance, especially on tire wear.
In order to make toe-in corrections it is known to make the bearing position on the body side of a wheel suspension link adjustable by having the suspension link bearing held by a kingbolt between supporting arms on the body side provided with slots running in the direction of the width of the vehicle for the kingbolt, so that the kingbolt can be set at different positions across the vehicle. This positioning is performed by cams which can rotate with the kingbolt, i.e. which are co-rotational with the kingbolt and are held between contact surfaces of the supporting arms which are spaced apart from one another in the adjusting direction, namely transversely of the vehicle. As soon as the position necessary for the desired toe-in is reached, the cams are set with respect to the supporting arms.
In one known system described in DE 4115110 A1, proof is provided that the toe-in maintenance was performed in the first inspection by placing additional adjusting disks between the cam and the supporting arms. The disks have a bore to accommodate the kingbolt and a projection on the supporting arm end which fits into the slot guiding the supporting arm. The adjusting disks thereby invariably define a position of the kingbolt with respect to the supporting arms. For the first inspection it is prescribed that these adjusting disks be removed, so that a readjustment has to be performed with the cams. The adjusting disks when removed serve as proof that the maintenance has been done.
In another known device for setting the toe-in as shown in DE 3200879 A1, the supporting arms of a control arm mounting on the body side are provided with recesses into which the position-centered adjusting disks can be placed. Bores therein accommodate the kingbolt of the control arm mounting. Different settings of the kingbolt, and thus also different toe-in settings, can be carried out by keeping adjusting disks on hand with different bore patterns, or two different settings, can be defined through the particular adjusting disk if the latter is turned 180.degree.. In the latter, the bore pattern assumed to be is not symmetrical with the particular axis of rotation.
Instead of fixing the adjusting disk by positioning it correctly in a recess in the supporting arm, provision is also made in the known device for providing the adjusting disk on its side facing the supporting arm with a projection which can be fitted into the kingbolt opening in the supporting arm which is oversized for the kingbolt, so that the result is thus a positioned mounting of the adjusting disk plus the desired positioning of the kingbolt in accord with the arrangement of the bore pattern for the kingbolt in the adjusting disk.
In these known systems, when adjusting the toe-in, only the preset toe-in, i.e., the toe-in with respect to an established spring position is changed, but the tilt of the toe-in curve in space remains fundamentally unaffected. To vary the tilt of the toe-in curve, methods independent of these above-described known methods have been applied, and the tilt of the toe-in curve is changed by making the elastic control arm bearings in the connection between the kingbolt and the suspension link adjustable such that the core and the outer sleeve of the suspension link are off-center from one another and rotatable. This signifies additional manufacturing expense and additional bearing variants.
Furthermore, a device for setting the toe-in and the tilt of the toe-in curve is described in DE 31 31 107 A1, in which the kingbolt carrying the bearing eye is adjustable, with respect to its supporting arms, by two eccentric systems independent of one another. Guides running transversely with respect to the vehicle are associated with the eccentrics of the one system and guides running vertically with respect to the vehicle are associated with the eccentrics of the other eccentric system. These guides lie with the corresponding adjusting disks on different sides of the supporting arms. An adjustment both transversely, i.e., the toe-in setting, and vertically, i.e., the toe-in tilt, is possible although at considerable cost, inasmuch as the arrangement of adjusting disks on both sides of the support arms plus the access necessary for their adjustment calls for an appropriate amount of space.